Clowns, it seems, are the monster of the moment on social media, even though many of the creepy stories have been debunked by police.

Photos and tales of sinister jokesters are popping out on Facebook, Twitter and Instagram, fueling panic as Halloween approaches. It's hard to say why clowns are this season's reigning bogeymen, but there are precedents for this candy-colored hysteria.

It started in England three years ago with a rogue Bozo nicknamed the Northampton Clown.

The Northampton Clown

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A college student and Stephen King fan frightened residents of a British town by dressing up as Pennywise, the sewer-dwelling jester from the novel "It."

In September and October 2013, Alex Powell would turn up on street corners clutching balloons and greeting pedestrians with Pennywise's catchphrase, "Beep beep."

Powell's friends took pictures of him in dark spots and created a Northampton Clown Facebook page to track his travels. It was a performance art prank that evolved into a viral phenomenon, replete with death threats from vigilante "clown catchers." A month after the Northampton Clown made his debut, a British newspaper, the Mirror, identified Powell as the culprit.

The Staten Island Clown

Not six months later, another mysterious figure began appearing across the pond in Staten Island, New York. Clad in a ruffled yellow suit, white gloves and oversize red shoes, the night-stalking funnyman was spotted at a train station near a Buffalo Wild Wings restaurant and at a school play, according to the Staten Island Advance.

The outer borough clown sightings caught the attention of author King, who suggested in a tweet that he should be receiving royalties.

The clown traipsed around town for a few days before a film company called Fuzz on the Lens revealed that the whole thing was staged to promote a movie.

The Wasco Clown

During October 2014, a California couple started an art project centered on portraits of a lonely clown with a head wound. The character posed for photos around the small town of Wasco, holding a knot of kaleidoscope balloons in such bleak locales as deserted parking lots, empty fields and abandoned playgrounds.

After the images went viral online, a teen copycat in nearby Bakersfield was arrested for wearing a clown costume and chasing a girl. Local police continued to get calls about scary clown sightings for weeks leading up to Halloween, but no further arrests were reported.

Clown costume ban in France

To prevent problems at a Halloween fest in southern France, a mayor ordered a holiday ban on clown costumes in 2014.

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As a result, Mayor Pierre Dudieuzere declared that people over the age of 12 were prohibited from wearing clown costumes and face paint at the village of Vendargues' Halloween parade. The clown-free celebration took place without incident.